Numerous exercise devices are available in the art. For example, U.S. Pat. No. 3,559,988 to Greenless, U.S. Pat. No. 5,897,471 to Multanen et al., and U.S. Pat. No. 5,980,436 to Cheng provide examples of such devices. While these devices may be suitable for the particular purposes that they address, they are not suitable for the purposes met by the present invention.
U.S. Pat. No. 3,559,988 to Greenless is drawn to a portable exercise device for developing the muscles of the wrists, arms and upper body. The device includes a spring having a coiled configuration in its unstressed condition, and a handgrip attached to each end of the spring operable to uncoil the spring upon relative twisting movement between the handgrips. The handgrips can be moved linearly toward and away from each other against the resistance of a spring force between the handgrips. While Greenless' device is portable and capable of exercising the wrists, arms and upper body, it is incapable of exercising the thigh muscles.
U.S. Pat. No. 5,897,471 to Multanen et al. is drawn to an upper body muscle toner device and leg and knee exerciser comprising a U-shaped flexure member and a pair of handgrips. The device is configured so that so that a person can grasp the handgrips to flex the U-shaped flexure member in and out with arm power to tone the upper body muscles and exercise the legs and knees. While Multanen et al.'s device can exercise the upper body muscles, legs and knees, it lacks a stabilizing feature for holding the device against the user when exercising the thighs. As a result, the device has a tendency to twist and slide while the user adducts and abducts the thighs making it difficult to maintain the device in a useable position.
U.S. Pat. No. 5,980,436 to Cheng is drawn to a thigh exerciser comprising a primary elongated member made of resilient material, two curved supporters engaged with two ends of the primary elongated member, a secondary elongated member detachably fitted in the primary elongated member, and two straps each extending through two slots of each of the curved supporters. While Cheng's device can be used to strengthen the thigh muscles, its application in exercising the upper body muscles is limited. In addition, Cheng's device comprises a linear member that is compressed into a curved formation by adducting the user's legs. Thus, Cheng's device is incapable of providing resistance to the abduction of the user's legs in exercising the outer thigh muscles.
What is needed in the art is a portable device that can exercise the muscles of the upper body and thighs while maintaining a stable, fixed position when used to exercise the thighs.